1. Field of the Invention
An embodiment of the present invention relates to an image forming device. Specifically, the embodiment relates to an ink supplying unit that is used for an inkjet recording device.
2. Description of the Related Art
For an inkjet recording device that is used for a printer, a facsimile machine, a copier, and a plotter as a single image forming device, the following configuration has been known. Namely, the configuration is for supplying ink from a main tank disposed in a device main body to a sub-tank disposed above a carriage. The sub-tank is a small capacity tank (a liquid container) for supplying ink, which is a liquid, to an inkjet head that is a liquid discharge head. The main tank is a large capacity ink cartridge that is a liquid reservoir tank.
In the configuration using the sub-tank, it is not necessary to mount a large ink tank on the carriage. Therefore, the configuration has advantages such that the power load for moving the carriage is reduced and oscillation caused by movement of the carriage is reduced.
The ink cartridge and the sub-tank disposed at the side of the carriage are connected through tubes. For example, a configuration has been adopted in which flexible tubes are utilized. The flexible tubes can follow the movement of the carriage, and the tubes themselves can also be moved. The tubes are extended along a main scanning direction in which the carriage moves. End portions of fluid channels of the tubes are connected to the main tank and the sub-tank, respectively. The tubes are folded at middle portions between the end portions. It looks like a U-shape in a planer view (e.g., Patent Document 1 (Japanese Registered Patent No. 4671884)).
Additionally, another configuration has been proposed. Namely, in the configuration, flexible tubes are bundled with and supported by a steel belt. Similar to the above-described configuration, the flexible tubes are bent in a U-shape and the flexible tubes can be moved to follow the movement of the carriage (e.g., Patent Document 2 (Japanese Patent Laid-Open Application No. 2008-149647)).
In the above-described configurations, the tubes are disposed above the carriage, so that the tubes do not interfere with the movement of the carriage.
Incidentally, in the inkjet recording device, an image is formed on a sheet of recording paper fed from a paper feeding unit by discharging ink droplets from the inkjet head while moving the sheet of recording paper on a platen facing the carriage in a sub-scanning direction. In the inkjet recording device, the sheet of recording paper that has moved on the platen is subsequently conveyed toward a discharging unit such as a paper discharging tray. When a conveyance failure such as paper jamming occurs, the sheet of recording paper may be removed.
For removing the recording paper that causes the conveyance failure, a space is provided in a conveyance path of the recording paper, so that the recording paper can be removed. However, the tubes in the above-described configurations are arranged in parallel with the moving direction of the carriage above the platen, and their upward positions, namely, their positions in the height direction, have been fixed to predetermined positions. Therefore, it may be difficult to enlarge the space for removing the sheet of recording paper.
FIG. 10 is a diagram illustrating the above-described circumstance. FIG. 10 shows a state where the inkjet recording device is viewed from a side surface. In FIG. 10, plural tubes A are arranged in parallel in the height direction so as to supply corresponding colors of ink. Above the platen B, both end portions of the tubes A in the conveyance direction of the sheet of recording paper (the direction indicated by the arrow), namely, the both end portions in a direction perpendicular to the main scanning direction of the carriage, are supported by corresponding tube guides C and D. One of the tube guides C and D (the tube guide indicated by the reference symbol C in FIG. 10) is disposed at a position F, at which discharging of the sheet of recording paper is started, at a side of a paper discharging guide E that discharges the sheet of recording paper that has passed through the platen B.
In FIG. 10, the position of the tube guide C is aligned with the position of the tube guide D in the height direction. Accordingly, the space H1 between the tube guide C, which is disposed at the side where the sheet of paper is discharged, and the paper discharging guide E in the height direction is limited to the space corresponding to the difference between the height of the paper discharging guide E and the height of the tube guide C, which is equal to the height of the tube guide D. Therefore, if the difference between the height of the paper discharging guide E and the height of the tube guides C and D is not sufficient for removing the sheet of recording paper, it may be difficult to remove the sheet of recording paper causing the conveyance failure on the platen B.
As a countermeasure to the problem, the following configuration has been proposed (e.g., Patent Document 3 (Japanese Registered Patent No. 2641200)). Namely, in the configuration, the tubes are disposed at a side portion of the carriage, instead of the portion above the platen. The inkjet recording device is divided into an upper unit and a lower unit. The upper unit includes the recording device main body and the carriage. The lower unit includes the ink tank. The upper unit is openable and closeable with respect to the lower unit. When the upper unit is opened, the tubes are stretched following the opening movement.
However, this configuration is different from the configuration in which the tubes are arranged above the platen.